| The electrical properties of ferroelectric memories are degraded when they are exposed to a hydrogen rich environment at elevated temperature. Hence, an encapsulated hydrogen diffusion barrier is essential for the integration of ferroelectric memory with existing Si technology. Thin films of alumina ("AlOx") and silicon nitride ("SiN") are studied as hydrogen barriers. Twelve wafers containing ferroelectric capacitors (FeCAP) with unique barrier layers were prepared by Texas Instruments Inc. by varying the barrier thickness and the deposition method. These wafers have been examined by Secondary Ion Mass Spectrometry (SIMS) and electrical measurements to determine the effectiveness of the barrier layer(s) in blocking hydrogen diffusion. To identify the effect of scaling on the extent of hydrogen damage of the ferroelectric memory, a region of small FeCAPs has been analyzed by SIMS. |
